/buk"euh rooh', buk'euh rooh"/ , n. , pl. buckaroos .
1. Western U.S. a cowboy, esp. a broncobuster.
2. Older Slang. fellow; guy.
[ 1820-30, Amer.; earlier bakhara, baccaro, bucharo vaquero, equiv. to vac ( a ) cow ( vacca ) + -ero -arius -ARY; perh. influenced by BUCKRA; later prob. reanalyzed as BUCK 1 + -EROO ]